In modern braking systems, vacuum brakes are being replaced by electromechanical and vacuum-free brakes (for example, the iBooster brake created by Robert Bosch GmbH). Electromechanical and vacuum-free brakes only use electrical energy during application of the brakes, which saves fuel and reduces CO2 emissions of the vehicle because energy from the combustion engine is not required to apply more pressure to the brakes.
Electromechanical brakes are controlled based upon sensor input (for example, a brake pedal travel sensor, a permanent magnet synchronous machine rotor position sensor, an permanent magnet synchronous machine current sensor, and the like). An electronic controller that controls the electromechanical brake receives feedback from the sensors in order to correctly operate the electromechanical brake. If the electronic controller does not receive feedback or receives faulty signals from the sensors, the electromechanical brake may be incorrectly controlled or not activated at all.